JPS5958210A - Anchor and sleeve for anchor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to self-cutting anchors or self-undercut anchors used in the construction industry for fixing anchors in concrete or stone. In particular, the present invention provides a self-expanding sleeve having a center portion which can be pushed down over a portion of a tapered expanding cone or expander in the root section in order to radially expand a pre-drilled hole. Regarding undercut anchors.

The use of self-perforating or self-trilinking anchors has become commonplace in the construction industry for several years. This type of anchor eliminated the need for two separate anchorages. That is, the first hole is drilled before inserting the self-drilling anchor, but the second drilling operation is performed when fixing the anchor inserted in the first hole. This is done by protruding the section to form an undercut or bell-shaped hole.

With the advent of self-drilling anchors, percussive or rotary drilling machines began to use expandable sleeves. The contact end of the sleeve was made expandable by cutting a slot of a predetermined length in the cylindrical surface or periphery of the sleeve. The slots were normally such that the sleeve could be easily ruptured, but this was only done when a spreading device was used during the fixing operation. Various wedge-shaped spreading devices have been used in spreading anchor devices such that the anchor is spread apart within an undercut hole or a bell-shaped undercut hole is formed. In all known devices, cutting teeth on the leading edge of the expandable sleeve remove concrete or other material.
The expandable sleeve is expanded outwardly or radially. However, this radial expansion can cause interference with unremoved concrete or side wall elements. This problem is extremely important in concrete. This is because interference or contact between the intermediately inserted sleeve and the surrounding concrete leads to crushing of the inner circumferential wall member and thus to excessive enlargement of the undercut hole. When a load is applied, this over-expansion allows the anchor to move in the direction of the applied force. The direction of this movement is into the over-enlarged hole, thus weakening the hole and reducing the holding force of the anchor.

It is most preferable for anchors fixed in concrete or other members such as stone to have their holding force limited by the forces of the anchor material and not by the forces of the concrete or sidewall members. It is desirable that this is not the case. If there is excessive enlargement of the pre-drilled hole, the holding force will be weakened due to crushing and collapse of the inner circumferential wall member. Typically, the anchor will be pulled out of its pre-drilled hole when subjected to a load that is less than the critical strength of the anchor material.

In other types of expandable sleeved anchor devices, the lower portion of the sleeve is attached to the top within a pre-drilled hole before being permanently forced into place through the use of a spreading cone or wedge. Preloaded ears are used that grip the inner circumferential wall member in the vicinity. However, these expandable sleeves typically suffer from similar drawbacks in that they cause the internal wall member to collapse and collapse, creating an over-enlarged hole, and when a heavy load is applied, the sleeve is pre-loaded. Despite the presence of the ears, the anchor tended to move in the direction of the applied load.

The above-mentioned problems have been overcome by the improved self-undercut anchor of the present invention, which does not over-enlarge the pre-drilled hole when securing the anchor.

The main object of the present invention is to provide a self-undercut anchor having an expandable sleeve that does not excessively enlarge a pre-drilled hole by collapsing the inner circumferential wall member in instant contact with the expanded fingers. Our goal is to provide the following.

Another object of the present invention is to create a sufficient gap between the outer periphery of both the cutting tooth and the extensible fingers following the cutting edge and the inner periphery wall member forming the side wall of the pre-drilled hole. An improved self-undercut anchor that prevents interference between the outer periphery of the sleeve and the inner peripheral wall member during the spreading operation in which the cutting edge removes the inner peripheral wall member. Our goal is to provide the following.

One feature of the present invention is that the improved self-undercut anchor uses a expandable sleeve with a reduced outer diameter in the area between the top of the cutting edge and just before the expansion slot. be.

Another feature of the invention is that the improved self-undercut anchor allows the sleeve to rest along and be forced apart during the anchoring operation.

The expansion having a tapered or angled surface consists in providing a cone or expander portion on the central bolt portion.

Another feature of the present invention is that the expanded diameter portion of the expanding cone or part of the expander is approximately 0.6 of the expanding slot length of the slot provided on the expandable sleeve.
It is between 1.5 times and 1.5 times.

An advantage of the present invention is that the improved anchor self-undercuts in a direction that does not reduce the retention force of the anchor.

Another advantage of the present invention is that the improved self-undercut anchor is simple in construction and easy to handle.

Another advantage of the present invention is to provide a self-undercut anchor in which retention of the anchor within the inner circumferential wall member is maximized.

These and other objects, features and advantages provide a self-undercut concrete for making expandable sleeves having reduced diameter areas directly above the cutting edges on the teeth of the expandable fingers. 1 This was achieved by preventing the outer circumferential surface of the finger-shaped member that can be pushed out from interfering with the inner peripheral wall member during the pushing and spreading operation when used in a lead anchor.

BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the invention will become apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings.

An improved self-cutting anchor, generally designated 10, is shown in side elevation in FIG. 1. FIG. Anchor 10 includes a central bolt portion 12 inside sleeve 14 . The central root section 12 has a recess 11 or reduced diameter section located between the tip section 15 and the expanding cone section 16. As best seen in the exploded view shown in Figure 2, the expander part 16
is tapered, with an increasing diameter portion 16a in which the outer diameter increases adjacent to the top end of the central bolt portion 12 and a decreasing outer diameter adjacent to the bottom or tip portion 15 of the central bolt portion 12. A gradually decreasing diameter portion 16b is formed. A recess 11, ie, a reduced diameter portion, is provided intermediate the expander portion 216 and the tip 15, and this recess 11 can be used to take in crushed debris during the insertion operation. Tip part 15
The center is conical so that the root portion 12 can be easily seated in a pre-drilled hole.

As best seen in Figure 2, the expander part 1
6 has a female threaded hole 18, and a threaded end 19 is screwed into the female threaded hole 18 so that the central bolt part 12 can be assembled. At the top of the central bolt part 12 is a fastening screw part 20 with a fixing thread, which is used to secure the object to be fixed after the anchor 10 has been pushed apart in the pre-drilled hole. It is provided.

The sleeve 14 shown in FIGS. 1 and 2 has at its top end a first end 17 or ring having a predetermined first outer diameter. A reduced diameter portion 22 and a shoulder portion 23 are disposed between the top and bottom portions of the sleeve 14, the shoulder portion 23 having a predetermined sixth outer diameter that is greater than the outer diameter of the reduced diameter portion 22. Fingers 21 extend downwardly from shoulder 23 to lower cutting or undercut teeth 28 .

A plurality of elongated slots 25 divide finger 21 and extend the entire axial length of shoulder 23. The undercut teeth 28 are angled outwardly and the sleeve 14 is best seen in FIG.
The outer periphery of the cutter is chamfered at an angle of about 15 degrees to form a cutting edge or cutting edge 24. This angle is selected so that the chamfered cutting edge 24 of the undercut tooth 28 fits downwardly over the increased diameter portion 16a of the expander portion 16 of the central bolt portion 12. be done. However, along the increased diameter portion 1ea, the cutting edge 2
Any angle may be used as long as it allows 4 to move downward.

The sleeve 14 has a generally cylindrical shape and is hollow so as to fit around the outer circumference of the central bolt portion 12. The surface of the finger-like member 210 is smoothed. The reduced diameter portion 22 of the sleeve 14 may have an outer diameter approximately 5% to 20% smaller than the first end 17 having a first outer diameter. The small diameter section 22 terminates at the end 17 of the sleeve 14, but is intentionally extended a sufficient length in the axial direction of the sleeve 14, so that the small diameter section 22 ends at the end 17 of the sleeve 14.
3 or more, preferably 1/2 or more of the axial length of the sleeve 14.

Similarly, in FIGS. 2 and 4, the outer surface or periphery of finger 21 is smaller than both the outer diameter defined by cutting edge 24 of undercut tooth 28 as a whole and the outer diameter of shoulder 23. The outer diameter is reduced.

FIG. 6 shows an alternative embodiment of the sleeve 14.

This sleeve 14 has a large diameter ring 33 adjacent to its top end.
and a slotted ring 27 at the top end. A hole 26 may be provided at the end of the spreading slot 25 to control the direction in which the crank spreads toward the body of the sleeve 14.

FIG. 6 best shows how the crack extends into the expansion slot 25, where the expansion crack 29 of the slot 25 in the sleeve is in the area of the small diameter section 22 of the sleeve 14. is shown extending upwards. In either embodiment, approximately 1.25 to 2.0 of the outer diameter of the first end 17
It has been found that a spreading slot 25 having a length in the range of double is desirable. The number of fingers used in sleeve 14 is approximately six to five. However, sleeve 1
If the outer diameter of finger-like members 21 is large, the number of finger-like members 21 may also be six or more.

The central bolt portion 12 may be formed from two separate pieces as shown in FIG. 2, or may be a one-piece expanding cone or expander without a female threaded hole 18 and a threaded end 19. It may also be formed as a central bolt portion with a portion. Increased diameter portion 16a of expander portion 16a
The actual length of the portion may be any length as long as it is longer than the length of the expansion slot 25, but ideally it is the axial length of the expansion slot 25 of the anchor sleeve 14. It was found that 0.6 to 1.5 times is better. Due to the cooperative interaction of the expansion slot 25 and the constant length section of the expander section 16, the sleeve 14 is arranged so that the small diameter section on the inclined surface of the enlarged diameter section 16a is connected to the fingers 21 of the sleeve 14. The expander portion 160 is driven downwardly on the conical surface until it is forced to interfere with the inner bore. Once this forced interference occurs, the expander portion 16 or expanding cone of the central joint 12 and the fingers 21 of the sleeve 14 are firmly engaged and held. This engagement and retention eliminated the need for tensioning the central bolt section 12.

As shown in FIG. 5, using an auxiliary tool 30 that fits around the retaining screw portion 20 and rests on top of the first end 17, the sleeve 14 is pushed into the expander portion 16 or expanded. It may also be propelled downwardly over the cone. A hammer may be used to propel the aid 30 and sleeve 14 downward. After the anchor 10 has been sufficiently stressed by forcing the sleeve 14 downwardly over the expander portion 16 as shown in FIG. A strongly tightened nut 31 may be fixed to the retaining screw portion 20.

FIGS. 5, 6 and 7 show the propulsion of the sleeve 14 with its center guided in the root portion 12 when the anchor 10 is loaded. In each figure, the anchor 10 is inserted into a pre-drilled hole 34. The inner diameter of the pre-drilled hole 34 is slightly larger than the outer diameter of the sleeve 14 so that the anchor 10 fits within the hole 34. Inner peripheral wall member 3, which is usually concrete
5 can be used to secure the anchor 10 via actuation of the fingers 21. In FIG. 5, the anchor 10 has just been inserted into the pre-drilled hole 34. An auxiliary tool 30 is placed on top of the sleeve 14 surrounding the set screw 20. Chamfered cutting edge 2
4 is seated on the enlarged diameter portion 16a of the expander portion 16. The tip 15 rests on the bottom of the pre-drilled hole 34.

When a load begins to be applied, as shown in FIG. 6, such as by hitting the top of the aid 30 with a hammer, the sleeve 14 begins to move downwardly over the expander portion 16. Each finger-like member 21 rides up on the increased diameter portion 16a of the expander portion 16, and the pushing-expanding slot 25 is pushed out from the lower end to move the finger-like member radially outward. I am made to do so. As a result of this radially outward movement, the cutting edge 24 of each undercut tooth 28 is directed against the side or inner circumferential wall member 35 of the pre-drilled hole 34.
start contacting. The cutting edge 24 starts cutting by itself and removes the inner peripheral wall member 35. As the sleeve 14 continues to move downward, the spreading slot 25 begins to rupture, forming a crack 29 in the spreading sleeve slot, as shown in FIG. When the sleeve 14 approaches the fully depressed position, the shoulders 23 are forced outwardly with their large outer diameter into the inner circumferential wall member 35 to form a second spreading anchor surface or 2, it acts as the surface of the fixing part.

The very important effect of the reduced diameter of the fingers 21 compared to the outside diameter of the chamfered cutting edge 24 and the outside diameter of the shoulder 23 is best seen in FIG.

FIG. 8 is an enlarged view showing that the finger-like members 21 are pushed outward in the radial direction, that is, expanded. The illustration shows that the cutting edge 24 removes the inner peripheral wall member 35 along a line that creates a gap between the inner peripheral wall member 35 and the outer periphery of the shaped member 21.

The outwardly expanding movement of the fingers 21 simultaneously moves the shoulders 23 outwardly into gripping engagement with the inner circumferential wall member 35. When fully loaded, the anchor 10 is firmly engaged with the inner peripheral wall member 25 with the lower cut or undercut area, but the self-cutting operation described above is not performed beforehand. The hole 34 will not be enlarged excessively, and the outer peripheral surface of the finger member 21 will not come into contact with the side wall of the pre-drilled hole 34 so strongly as to crush or destroy the inner peripheral wall member 35. .

This prevention of excessive expansion of the pre-drilled hole 34 is achieved by reducing the outer diameter of the finger member 21 by the action of the diameter reduction part and by the action of the region of the small diameter part 22 directly above the shoulder part 23. It was done. Relatively short pushing and spreading slot 2
5, the area where the outer diameter of the finger member 21 is reduced, and the small diameter portion 22 cooperate to form an inner peripheral wall member 3 formed by a portion of the sleeve 14 that is pushed outward in the radial direction.
5 is carried out in such a manner as to prevent the inner peripheral wall member 35 forming the side wall from collapsing and to prevent the pre-drilled hole 34 from excessively expanding.

Since the outer surface of the sleeve 14 that can be pushed out has a substantially smooth shape, the stress is transferred to the inner peripheral wall member 35.
Evenly distributed over a wide area.

The removed inner peripheral wall member 35 falls downward into the pre-drilled hole 34.

When the sleeve 14 is moved downward beyond the increased diameter portion 16a of the expander portion 16 and the expander portion 16 reaches a position above the expansion slot 25, the expansion is completed. Gashi is completed. This position is sensed by the operator by indicating full extension of the sleeve 14 when the downward movement of the sleeve 14 ceases. The contact between expander portion 16 and the inner surface of sleeve 14 increased the stiffness and retention of anchor 10.

While preferred embodiments based on the principles of the invention have been illustrated and described, it will be appreciated that the invention is not limited to such specific embodiments, and that the invention may be practiced in a wide variety of other ways. It is. The claims of the invention are intended to cover all readily available changes in detail, materials and arrangement of parts that may occur to one skilled in the art in view of the above disclosure.

[Brief explanation of the drawing]

FIG. 1 is a side elevational view of a self-cutting fixing IF or self-undercanting anchor according to an embodiment of the present invention, showing a central bolt portion having a portion of an expander and a sleeve fitted around the outer circumference of the central bolt portion. , FIG. 2 shows a deployment side elevational view of the self-undercut anchor shown in FIG. 1, and FIG. 3 shows a modified embodiment of the push-7 expandable sleeve shown in FIG. FIG. 4 is a perspective view shown in the open position showing rupture or cracking along the line defined by the slot in the sleeve; 5, 6 and 7 are partial cross-sectional views of the unexpanded sleeve, showing the reduced diameter at the top of the cutting edges of the teeth attached to the extensible fingers; FIGS. The expanding conical part of the central bolt part, that is, the sleeve that can be pushed out along a part of the expander, makes an undercut by itself ~ it is pushed downward into the pre-drilled hole and fixed. FIG. 8 is a partially enlarged side elevational view of one of the expandable finger-like members of the expandable sliding lower slide, and shows how the cutting edge of the tooth touches the inner peripheral wall member. and how the reduced diameter portion prevents interference with the inner circumferential wall member while the shoulder portion forms a second retaining surface with the inner circumferential wall member. show. 10...Anchor, 12...Central bolt, 14...
・Slip 6 -7", 15... Tip, 16... Expander part, 16a... Increased diameter part, 16b... Decreasing green part, 1
7... First end portion, 21... Finger-like member, 22...
Small diameter part, 23... Shoulder part, 24... Cutting edge, 25...
Slot (elongated slot), 28...teeth, 32...
・Object to be fixed (object), 34... pre-drilled hole,
35...Inner peripheral wall member (side wall part). Agent Asamura Kōgai 4 people 4

Claims (1)

[Scope of Claims] (1) An anchor for fixing an object to concrete by being inserted into a pre-drilled hole having an elongated side wall, comprising: (a) a first end formed with a tip; (b) a central bolt portion of a predetermined length having an opposite second end; (b) an increased diameter portion formed on the central bolt portion adjacent the second end; an expander portion having a reduced diameter portion adjacent a tip portion; (C) a predetermined inner circumference and a predetermined axial direction fitable about the second end of the central bolt portion; a hollow expandable sleeve having a length, the sleeve having a first end having a first outer diameter, and an elongated sleeve having a predetermined length, width, and predetermined outer circumference; and a second end portion provided with a plurality of finger-like members that can be pushed out outwardly; a plurality of elongate slots defining a width; (e) a reduced diameter portion on the sleeve adjacent the first end and extending into at least a portion of the elongate slot; a shoulder portion capable of grippingly engaging the side wall portion of the pre-drilled hole when the sleeve is expanded;
the shoulder has a third outer diameter that is greater than the reduced diameter portion and a predetermined axial length that is shorter than the finger;
and a shoulder section separated by said elongated slot extending past said waste section; attached teeth having chamfered cutting edges; the cutting edges of the surface, at least one attached to each of the fingers, collectively define a fourth outer diameter;
The outer circumference of the finger-like member is smaller than both the sixth outer diameter of the shoulder and the fourth outer diameter defined by the cutting edge, and a load is applied to the sleeve. When the sleeve is expanded by the expander portion of the central bolt portion by forcibly pushing down the expander portion upwardly, the outer periphery of the finger-like member is forced downwardly. The cutting edge attached to each of the fingers is adapted to undercut itself within the pre-drilled hole without engaging the side wall of the pre-drilled hole. Features an anchor. (2. The anchor according to claim 1, wherein the cutting edge has an inner surface, and when the sleeve is fitted to the central bolt portion before a load is applied to the anchor, 3. The anchor of claim 1, wherein the inner surface is adapted to seat on the expander portion of the central bolt portion. An anchor whose diameter is about 1.25 to about 2.0 times the first outer diameter. (4) In the anchor according to claim 1, the number of the finger-like members is 6 to 6. (5) The anchor according to claim 1, in which the number of finger-like members is about 4. (6) Scope of Claims No. The anchor according to claim 1, wherein a portion of the central bolt portion adjacent to the second end is threaded. is a conical anchor. (8) The anchor is inserted into a pre-drilled hole having an elongated side wall and is adapted to be fitted into a swivel of a central joint having an expander portion. , a hollow expandable sleeve for a concrete anchor having a predetermined axial length, comprising: (a) a first end having a first outer diameter; and (b) a predetermined length. and (c) an opposite second end portion having an outer periphery and provided with a plurality of elongated and outwardly pushable finger-like members; and (c) a plurality of finger-like members defining each of the finger-like members. (d) a small diameter portion intermediate the first end and the opposite second end; and (e) the pre-opened slot when the sleeve is unfolded. a shoulder portion capable of gripping engagement with the side wall portion of the hole;
the shoulder has a third outer diameter that is greater than the reduced diameter portion and a predetermined axial length that is shorter than the finger;
and (f) a shoulder at least partially separated along its axial length by a plurality of said elongated slots; and (f) on each said finger on said second end of said sleeve. at least one tooth having a chamfered cutting edge; the cutting edges of the teeth, at least one each attached to each of the fingers, collectively define a fourth outer diameter. define,
The outer circumference of the finger member is smaller than both the sixth outer diameter of the shoulder portion and the fourth outer diameter defined by the cutting edge, and the outer circumference of the expander of the central built portion When the sleeve is pushed open by the section, the cutting edge attached to each of the fingers does not engage the outer periphery of the finger with the side wall of the pre-drilled hole. An anchor sleeve characterized in that it is adapted to undercut itself in a pre-drilled hole. 9. The anchoring sleeve of claim 8, wherein the plurality of elongated slots extend axially past the shoulder to the reduced diameter portion. In the sleeve according to claim 8,
The length of the plurality of elongated slots is 1.25 times to about 2.0 times the force of the first outer diameter. (11) The anchor sleeve according to claim 8, wherein the number of finger-like members is about 3 to 5. a2. The anchor sleeve according to claim 8, wherein the number of finger-like members is four. (L) The sleeve for an anchor according to claim 8, wherein a portion of the central bolt adjacent to the second end is threaded.